Apparatus for cracking hydrocarbon oils



G. EGLOFF ET AL APPARATUS FOR CRACKING HYDROCARBON OILS Original FiledJuly 6, 1920 Dec. 8, 1931.

Fatented Dec. 8, 1931 UNITED ySTATI-:s

PATENT OFFICE GUSTAN' EGLOFF AND HARRY P. BENNER, 0F CHICAGO, ILLINOIS, 4 A.SSIG'NORS T0 UNIV ERSALOIL PRODUCTS COMPANY,. OF CHICAGO,v ILLINOIS, A `Clfl'7"1"fl'lfl' *OF SOUTH DAKOTA APPARATUS Fon GRACKING HYDROCARBON oILs Application led July 6,4920, Serial No. 394,083.V rRenewed March 15, 1928.

Among the salient objects of your invention are to provide anapparatus for thermal and pressure distillation of heavy hydrocarbon oils to produce light oil therefrom by means of a double pressure still, a carbon settling tank and spraying oil over the surface of the oil in the upper still of-the double pressure stills; to provide an apparatus for producing light oils from heavy oils by means of pressure distillation in a double pressure still while pumping raw oil into the lower still of the double pressure still; to provide an apparatus for thermal and pressure distillation of hydrocarbon oils yto produce gasoline or other light oils therefrom by means of mixing the relatively cool dephlegmated oil with raw oil and pumping same to the bottom of the lower still of the double pressure stills; to provide an apparatus for pressure distillation in which the carbon and heavy oil from the,

lower pressure still are drawn into a settling tank having baie plates therein to settle out the carbon and draw the carbon free oil by means of a pump and spraying said oil upon the liquid of the upper still of the double pressure stills; to provide an apparatus for the pressuredistillation of hydrocarbon oils to produce light oils by means of a double pressure still, a carbon settling tank, a pump to circulate the oil from said settling tank to the upper still of the double pressure stills, a diverting of the dephlegmated oil to the lbottom of the lower still of the double pressure stills and to pump raw oil continuously into the system through the lower pressure still of the double pressurestills, and in general to provide an improved apparatus of the character referred to.

'In the drawing, the single igureillustratesa View partly in side elevation and partly in vertical section of our novel form of apparatus used in carrying 'out our process.

Referring to the drawing, 1 designates a gas burner,'2 the-furnace provided with a bridge wall 2a and stack 2b. In the furnacey is mounted the still which, as shown, may

consist of a pair of cylindrical shells 3 and 4,'

the former mounted below and the latter above bridge wall 2a. These shells 3 and 4 are connected by means of the pipes or conduits 5, the upper ends o'f which preferably project above the bottom of the shell 4. To

7b and 7c connected by right angle pipes 7 d.

The vapors pass from the dephlegmator 7a by means of line 9a to coil 8 seated in water condenser 8. The coil 9 `is connected by pipe 95 to receiver 10. This receiver 10 is provlded with pressure gauge 11 and liquid level gauges 12 and 13. It is also providedwith gas outlet 14 controlled by 'throttle valve 15 and liquid draw oli' 16'controlled by throttle valve 17.

`Charging stock or fresh oil is fed to the shell 3 from'charging line 18 connected to pump 2O leading to any suitable source of supply. A valve 21 may be interposed in the charging line if desired.- VThe reflux condensate which falls backfrom dephlegmator 7 a passes through pipe 7 into branch 22 which shell 4. Preferably the shell 3 .is normally" l kept threequarters full of liquid. The temperature to which shell 4 is subjected is normally high enough so that the vapors in shell 4 will be superheated. Oil is continuously drawn off throu h linel 20a controlled by valve 20?) into the ottom of the carbon settling' tank 21a. This tank 21a is provided witl'bale's 22a and 23a which tend to cause j thecarbon to precipitate out into the bottom of this tank. This carbon settling tank is provided with manhole plate (not shown) so that' it can bereadily cleaned out.` The heavier oil containing a maximum amount of carbon is drawn olfthrough line 25 controlled by valve 26. The cleaner oil passes through line 24a controlled by valve 27 to pump 28 j whence `it is returned by lin 29 into the upper end of theshell 4. This line 29 terminates in a perforated ipe 30 extending horizontally through the s ell 4. A valve 31 is preferably interposed in line 29. The hot oil which passes through the perforated pipe 30 isin part vaporized and the unvaporized portion can pass out through pipes 5 into the shell 3 flowing counter-current to the' ascending vapors. rIhe lines 22, 24, a, settling tank` 21a, pipe 24a and pipe 29` are preferablyl lagged or insulated so as to prevent as far as possible any reduction in temperature of p the oil passing therethrough.

The following description of the operation of the process may be given. i Theshell 3 is charged and kept charged toapproXima-tely 75% of its capacity with say a mid-continent gas oil of 32 Baume gravity. The oil temperature in the shell 3`may be 7 50 F. while the vapors that pass to shell- 4 may be subjected to a vapor temperature of 820 F. A

pressure f 105 pounds may be maintained on the entire system by suitably regulating the valves in the receiver 10 and the residuum draw-off valve 26. If desired, a differential pressure may be maintained by regulating the valve 32 interposed between line 9a and dephlegmator 7 a. By regulating this valve 32 a pressure ofv 100 lbs. may be,maintained on the still and dephlegmator and a pressure of lbs. on the water condenser and receiver or atmospheric pressure on the latter. These shells 3 and 4 may each be of 6 diameter 4and 30 long with the rest of the apparatus approximately the proportionate size shown in the drawing. By means of this process, 65% of the gas oil may be converted into pressure distillate having a gravity of 51 Baum and upon the basis of raw oil treated 36%,of oil maybe thus converted into 58 Baumel gravity gasoline. f

The following modification of the process f may be described. Instead of filling the shell dephle cracke still 3 three quarters full of oil, the oil may be'fed in sufficient quantity into the still so as to maintain a liquid level of approximately of the total capacity of the entire still.

In other words the liquid level of the Aoil will be maintained in shell 4 slightly below the perforated pipe 30. In certain cases it may be desirable to carry out the modified process, as for example in refractory or oils ditlicult to crack such as Pine Island gasoil, kerosene,

steam still bottoms'or Mexican gasoil, itis advisable to have a maximum heating area per gallon of oil treated compared to the ation surface for there are easily oils such as heavy asphaltic insthe character of the type of Iola crude, fuel oil from wayside fields of Kansas, residuums or the like which require much less radiating surface in relationship to lieating surface for equivalent production of result from said hydrocarbon oils.

With reference to the novel form of apparatus it is to be noted that'the double pressure still shown permits of the use of smaller 4units which have a much greater factor of safety than a single shell of the same capacity. In addition a maximum heating area is obtained for a given capacity and also by means of this apparatus the vapors can be readily superheated.

` We claim as our invention:

-1. An apparatus for cracking oil, comprising a furnace, a pair of shell stills therein,

and a plurality of communications between said stills, means for supplying raw oil directly to the lower still, the. vapors passing through said communications into the upper still to be superheated therein, means for discharging unvaporized oil from the lower still, f

to a settling zone wherein the oils free carbon content isI precipitated, and means for delivering the carbon free oil to the upper still to contact witli the ascending vapors during its passage to`\the lower still.

2. An apparatus for cracking oil, comprising a furnace, a pair of shell stills therein, fand a plurality of communications between said stills, means for supplying raw oil directly to the lower still, the vapors passing through said communications into the upper still t'o be superheated therein, means for withdrawing oil from the lower still, a set- 

